[Top] [All Lists]

Re: [ontolog-forum] Logic, Datalog and SQL

To: "[ontolog-forum]" <ontolog-forum@xxxxxxxxxxxxxxxx>
From: "John F. Sowa" <sowa@xxxxxxxxxxx>
Date: Thu, 08 Feb 2007 21:53:25 -0500
Message-id: <45CBE225.7050806@xxxxxxxxxxx>
Pat,    (01)

I'd rather not stir up more debate on this topic, but I
would like to say that one can make a good case for the
claim that there is general notion of model that includes
both as special cases.    (02)

 > Oh, sure. But here you are using "model" in what I
 > called the model-2 sense, right, rather than the Tarskian
 > sense used in "model theory". Then this becomes the
 > Korzybskian slogan that the map is not the territory:
 > which is true, of course.    (03)

In my 1984 book, I mentioned with approval an observation by
Carl Adam Petri, of Petri-net fame.  At the end of this note
is a copy of the passage in which I summarize Petri's point.    (04)

I still believe there is an important core meaning of _model_
that is common to these uses of the word, to the term "mental
model", and to the Craik-Minsky notion of the brain as a
machine for building models.    (05)

_______________________________________________________________    (06)

 From J. F. Sowa (1984) _Conceptual Structures_, Addison-Wesley,
Reading, MA, p. 20:    (07)

The word _model_ has multiple meanings in engineering, logic, and common 
speech. Petri (1977) noted three different meanings in the phrases model 
of an airplane, model of an axiom system, and model farm:    (08)

     * Simulation. A model airplane is a simplified system that 
simulates some significant characteristics of some other system in the 
real world or a possible world.    (09)

     * Realization. A model for a set of axioms is a data structure for 
which those axioms are true. Consistent axioms may have many different 
models, but inconsistent axioms have no model.    (010)

     * Prototype. A model farm is an ideal or standard for evaluating 
other less perfect farms or for designing new ones.    (011)

Petri maintained that a common basis should be found for these three 
different ways of modeling.    (012)

Citation:    (013)

Petri, Carl Adam (1977) "Modelling as a communication discipline,"
in H. Beilner & E. Gelenbe, eds., _Meaning, Modelling, and
Evaluating Computer Systems_, North-Holland Publishing Co.,
Amsterdam, pp. 435-449.    (014)

Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/  
Subscribe/Config: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/  
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/ 
To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx    (015)

<Prev in Thread] Current Thread [Next in Thread>